Nā nīnau hoʻohālike a me ke kūkākūkā ʻana o nā pilina intermolecular
He kumuhana koʻikoʻi ka pilina intermolecular i ke kemika, ʻoiai hoʻi i ka hoʻomaopopo ʻana i nā ʻano kino a me nā kemika o nā mea. Hoʻokomo pū ka pilina intermolecular i nā mana hoʻopuehu Lākana, nā mana dipole-dipole, a me nā pilina hydrogen. ʻO ka hoʻomaopopo piha ʻana i kēlā me kēia ʻano pilina a pehea lākou e launa pū ai he mea nui ia no ka wānana ʻana i ke ʻano o nā mea ma lalo o nā kūlana like ʻole. E kūkākūkā kēia ʻatikala i kekahi mau pilikia hoʻohālike a me kā lākou mau hoʻonā e kōkua i ka wehewehe ʻana i kēia manaʻo.
1. Kaila Ladana (Nā Mana Hoʻopuehu)
ʻO nā mana o Ladana ke ʻano nāwaliwali loa o nā mana van der Waals. Kū mai lākou mai ka pilina ma waena o nā dipoles manawa pōkole e hana ʻia i ka wā e lilo ai ka hoʻolaha ʻana o nā electrons i loko o ke ao electron o kahi mole i mea like ʻole no kekahi manawa.
Laʻana Nīnau 1:
Nīnau:
ʻElua mau molekala non-polar, e ʻōlelo kākou ʻo He lāua ʻo Ne, he mau mana Lākana ko lāua ma waena. No ka mea, ʻoi aku ka nui o Ne ma mua o He, e wehewehe i ka mea nona nā mana Lākana ikaika, a no ke aha?
Kūkākūkā:
ʻOi aku ka nui o nā mana o Lākana i ka piʻi ʻana o ka helu o nā electrons i loko o kahi molekala, ʻoiai e hoʻonui ana kēia i ka polarizability. ʻOi aku ka nui o nā electrons o Neon (Ne) (10) ma mua o Helium (He) nona 2 mau electrons wale nō. No laila, ʻoi aku ka nui o ke ao electron o nā molekala Ne a ʻoi aku ka maʻalahi o ka polarization ma mua o He. ʻO ka hopena, ʻoi aku ka ikaika o nā mana o Lākana ma waena o nā molekala Ne ma mua o waena o nā molekala He.
2. Mana Dipole-Dipole
Hana ʻia nā mana Dipole-dipole ma waena o nā molekala polar kahi e launa pū ai ka hoʻopiʻi maikaʻi hapa o kekahi molekala me ka hoʻopiʻi maikaʻi ʻole hapa o kekahi molekala ʻē aʻe.
Laʻana Nīnau 2:
Nīnau:
ʻElua mau molekala polar, ʻo HCl lāua ʻo HF, he mau mana dipole-dipole. Ma waena o HCl lāua ʻo HF, ʻo wai ka mea i ʻoi aku ka ikaika o nā mana dipole-dipole a no ke aha?
Kūkākūkā:
ʻOi aku ka ikaika o nā mana dipole-dipole o nā molekala HF ma mua o HCl. ʻO kēia no ka mea he kiʻekiʻe loa ka electronegativity o fluorine (F), a ʻoi aku ka nui o ka ʻokoʻa electronegativity ma waena o H a me F ma mua o ka mea ma waena o H a me Cl. Hoʻokumu kēia i kahi dipole ikaika i loko o ka molekala HF ma mua o HCl. No laila, ʻoi aku ka ikaika o nā mana dipole-dipole ma waena o nā molekala HF ma mua o nā mea ma waena o HCl.
3. Nā Hoʻopaʻa Hydrogen
ʻO ka hoʻopaʻa hydrogen kahi ʻano kūikawā o ka ikaika dipole-dipole a hana ʻia ke launa pū kahi ʻātoma hydrogen i hoʻopaʻa ʻia me kahi ʻātoma electronegative kiʻekiʻe (e like me F, O, a i ʻole N) me kahi pālua electrons ma kekahi ʻātoma electronegative kiʻekiʻe.
Laʻana Nīnau 3:
Nīnau:
E noʻonoʻo i kēia mau mea ʻekolu: ka wai (H₂O), methanol (CH₃OH), a me ka ethanol (C₂H₅OH). E hoʻoholo i ka mea nona ka pilina hydrogen ikaika loa, a no ke aha?
Kūkākūkā:
Hiki i nā mea āpau i ʻōlelo ʻia ke hana i nā pilina hydrogen no ka mea he mau hui –OH ko lākou. Eia nō naʻe, ʻo ka ikaika o kahi pilina hydrogen ʻaʻole wale ma ke alo o ka hui –OH akā ma ka helu a me kahi o nā wahi i hiki ke hana i nā pilina hydrogen.
– Hiki i ka wai (H₂O) ke hana i ʻehā mau pilina hydrogen (ʻelua ma ke ʻano he mea hāʻawi ma o ka ʻātoma H a ʻelua ma ke ʻano he mea ʻae ma o ka hui electron lone ma O).
– Hiki i ka Methanol (CH₃OH) a me ka ethanol (C₂H₅OH) ke hana i ʻelua mau pilina hydrogen (hoʻokahi ma ke ʻano he mea hāʻawi ma o H a hoʻokahi ma ke ʻano he mea ʻae ma o ka lone pair ma O).
No laila, hiki i ka wai (H₂O) ke hana i nā pilina hydrogen nui loa a no laila he ikaika loa nā pilina hydrogen.
4. Ka hui pū ʻana o ka Mana o Lākana a me ka Mana Dipole-Dipole
I kekahi mau mea, hiki i ka hui pū ʻana o nā mana Lākana a me nā dipole-dipole ke hana a kōkua i ka ikaika holoʻokoʻa o nā pilina intermolecular.
Laʻana Nīnau 4:
Nīnau:
E hoʻohālikelike i nā kiko paila o ka chloroform (CHCl₃) a me ke kalapona tetrachloride (CCl₄), a wehewehe i ke kuleana o nā mana Lākana a me nā dipole-dipole i kēia.
Kūkākūkā:
– He molekala polar ʻo Chloroform (CHCl₃) me kahi manawa dipole piha ma muli o ka hoʻolaha like ʻole o nā electrons e pili ana i nā ʻātoma H.
– He molekala non-polar ka carbon tetrachloride (CCl₄) ma muli o kona hoʻolaha electron symmetrical ʻoiai he ʻātoma Cl electronegative kiʻekiʻe loa.
E ikaika ana nā mana dipole-dipole ma CHCl₃ ma muli o ka polarity o ka molekala, ʻoiai e koʻikoʻi ana nā mana Ladana ma nā molekala ʻelua ʻoiai ʻoi aku ka nui o CCl₄ a loaʻa paha kahi ao electron polarizable.
Eia nō naʻe, ʻo ka hui pū ʻana o nā mana Ladana a me nā mana dipole-dipole i loko o CHCl₃ e hoʻonui ai i kona kiko paila ma mua o CCl₄, ʻoiai he mau kaumaha molekala like ko lākou.
5. Nā Hana like ʻana o ka Ion-Dipole
He mea nui nā pilina ion-dipole i ka hoʻoheheʻe ʻia ʻana o nā paʻakai i loko o nā mea hoʻoheheʻe polar e like me ka wai. Hoʻoikaika kēia ʻāpana i ke koʻikoʻi o ka hoʻouka ion a me ka kokoke ʻana i nā dipoles mole solvent.
Laʻana Nīnau 5:
Nīnau:
No ke aha e hoʻoheheʻe maʻalahi ai nā paʻakai e like me ka sodium chloride (NaCl) i ka wai?
Kūkākūkā:
Ua haku ʻia ka sodium chloride me nā ion Na⁺ a me Cl⁻. He molekole polar ka wai (H₂O) me kahi uku maikaʻi ʻole hapa ma ka oxygen a me kahi uku maikaʻi ma ka hydrogen. Ke hoʻoheheʻe ʻia ʻo NaCl i loko o ka wai, pili nā ion Na⁺ me ka hopena oxygen o ka molekole wai, ʻoiai pili nā ion Cl⁻ me ka hopena hydrogen. He ikaika kēia mau pilina ion-dipole e lanakila ai i nā mana ionic i loko o ke kristal NaCl, e ʻae ana i ka paʻakai e hoʻokaʻawale a hoʻoheheʻe.
Pani
ʻO ka hoʻomaopopo ʻana i nā ʻano pilina intermolecular like ʻole, e like me nā mana Ladana, nā pilina dipole-dipole, nā pilina hydrogen, a me nā pilina ion-dipole, he mea nui ia no ka wānana a me ka wehewehe ʻana i nā ʻano kino a me nā kemika o nā mea. ʻO nā laʻana a me nā kūkākūkā i hōʻike ʻia ma kēia ʻatikala me ka manaʻolana e hāʻawi i kahi kiʻi maopopo a hoʻoikaika i nā manaʻo kumu o ka pilina intermolecular. He mea pili kēia ʻike ʻaʻole wale i ka ʻepekema kumumanaʻo akā i nā noi hana e like me ka ʻenekinia mea, nā lāʻau lapaʻau, a me ka ʻepekema kaiapuni.
